if you are trying to reach your arduino from outside your dlink router, you will need to use your wan ip address (or a service like no-ip.com), and have the dlink port forward the outside request to the lan ip address of your arduino.

Google forum search: Use Google Search box in upper right side of this page. Why I like my 2005 Rio Yellow Honda S2000 https://www.youtube.com/watch?v=pWjMvrkUqX0

My code is the very same no changes WEBSERVER ethernet example that comes with the Arduino 1.0 IDE ONLY the IP address that is 192.168.0.104 + the MAC address is changed and the Server port rest is the same.

I looked at the screen shot, and looks fairly straight forward to enter the lan ip address used by the arduino server.

edit: if you want to use a port other than 80, then set the public port start to something 81 and the public port end to something like 91. This should allow any outside request that are wanting to access ports 81 thru 91 to be forwarded to the arduino.

Google forum search: Use Google Search box in upper right side of this page. Why I like my 2005 Rio Yellow Honda S2000 https://www.youtube.com/watch?v=pWjMvrkUqX0